Aliphatic Polyester Resin Compositions and Shaped Articles

Abstract

Aliphatic polyester resin compositions capable of being shaped into a shaped article are disclosed. Shaped articles comprising aliphatic polyester resin compositions are also disclosed. The shaped articles possess excellent transparency, flexibility and heat resistance.

1 - 18 . (canceled)  
   
   
       19 . An aliphatic polyester resin composition comprising: 
 (A) a crystalline aliphatic polyester resin having a melting point of 100° C. to 180° C. that is derived from an asymmetric aliphatic hydroxycarboxylic acid containing at least 90.5 wt % of a L-form enantiomer or a D-form enantiomer of the acid.    (B) a plasticizer selected from the group consisting of glycol derivatives, glycerin derivatives, phthalic acid derivatives, adipic acid derivatives, azelaic acid derivatives, sebacic acid derivatives, maleic acid derivatives, fumaric acid derivatives, trimellitic acid derivatives, citric acid derivatives, fatty acid derivatives, sulfonic acid derivatives, phosphoric acid derivatives, paraffin derivatives, diphenyl derivatives, epoxy derivatives and aliphatic polyesters, and    C) a solvent in which the crystalline aliphatic polyester resin and the plasticizer have solubility, wherein the solvent (1) has a boiling point lower than the melting point of the crystalline aliphatic polyester resin, (2) is present in an amount of 10 to 200 parts by weight per 10 parts by weight of a total weight of the crystalline aliphatic polyester resin and the plasticizer, and (3) comprises a ketone-based solvent, wherein the aliphatic polyester resin composition is in a solution state.    
   
   
       20 . The aliphatic polyester resin composition to  claim 19 , wherein the crystalline aliphatic polyester resin is a polylactic acid.  
   
   
       21 . The aliphatic polyester resin composition of  claim 19 , wherein the plasticizer has a glass transition point of 25° C. or less and a molecular weight of 10,000 to 1000,000.  
   
   
       22 . The aliphatic polyester resin composition of  claim 19 , wherein the plasticizer has a molecular weight of 100 to 1,000.  
   
   
       23 . The aliphatic polyester resin composition of  claim 19 , wherein the plasticizer is present in an amount of from 5 to 100 parts by weight per 100 parts by weight of the crystalline aliphatic polyester resin.  
   
   
       24 . The aliphatic polyester resin composition of  claim 19 , wherein the solvent is 2-butanone or cylopentanone.  
   
   
       25 . The aliphatic polyester resin composition of  claim 19 , wherein the crystalline aliphatic polyester resin has a weight average molecular weight of from 90,000 to 500,000.  
   
   
       26 . A shaped article obtained by shaping without stretching the aliphatic polyester resin composition of  claim 19  wherein the shaped article has a modulus of 1×10 6  to 1×10 9  Pa at a temperature of 25° C. to 100° C. as measured in accordance with JIS K-7233-4. and a transparency clouding value of 20% or less as measured in accordance with JIS K-7105.  
   
   
       27 . A method of forming the said articles of  claim 26 , wherein the method comprising the steps of: 
 preparing the aliphatic polyester resin composition; and    shaping the composition wherein the shaping step comprises injection molding injection blow molding, thermal molding, compression molding, inflation molding, T-die molding, or coating the composition onto a substrate and drying the solution, wherein the shaped article is formed without a stretching step.    
   
   
       28 . The shaped article of  claim 26 , wherein the shaped article comprises a film or a fiber.  
   
   
       29 . The shaped article of  claim 26 , wherein the shaped article has a thickness such that the shaped article is unstretchable.  
   
   
       30 . The shaped article of  claim 26 , wherein the crystalline aliphatic polyester resin is a polylactic acid.  
   
   
       31 . A method of forming a shaped article having a modulus 1×10 6  to 1×10 9  Pa at a temperature of 25° C. to 100° C. as measured in accordance with JIS K-7233-4, and a transparency clouding value of 29% or less as measured in accordance with JIS K-7105, said method comprising the steps of: 
 preparing an aliphatic polyester resin composition comprising: 
 (A) a crystalline aliphatic polyester resin having a melting point of 100° C. to 180° C. that is derived from an asymmetric aliphatic hydroxycarboxylic acid containing at least 90.5 wt % of an L-form enantiomer or a D-form enantiomer of the acid,  
 (B) a plasticizer selected from the group consisting of glycol derivatives, glycerin derivatives, phthalic acid derivatives, adipic acid derivatives, azelaic acid derivatives, sebacic acid derivatives, maleic acid derivatives, fumaric acid derivatives, trimellitic acid derivatives, citric acid derivatives, fatty acid derivatives, sulfonic acid derivatives, phosphoric acid derivatives, paraffin derivatives, diphenyl derivatives, epoxy derivatives and aliphatic polyesters, and  
 (C) a solvent in which the crystalline polyester resin and the plasticizer have solubility, wherein the solvent (1) has a boiling point lower than the melting point of the crystalline aliphatic polyester resin, (2) is present in the amount of 10 to 200 parts by weight per 10 parts per weight of a total weight of the crystalline aliphatic polyester resin and the plasticizer, and (3) comprises a ketone-based solvent; and  
   shaping the composition, wherein the shaping step comprises injection molding, extrusion blow molding, extrusion stretch-blow molding, injection blow molding, injection stretch-blow molding, thermal molding, compression molding, inflation molding, T-die molding, or coating the composition onto a substrate and drying the solution.    
   
   
       32 . The method of  claim 31 , wherein the shaping step comprises removing at least a portion of the solvent by drying the composition.  
   
   
       33 . The method of  claim 31 , wherein the shaping step comprises an extrusion step.